The conventional wisdom is that unlimited contributions by wealthy donors will benefit Republicans more than Democrats because, well, rich people tend to be Republicans, and really rich people tend to be really Republican. There are exceptions, of course. Democratic billionaires like George Soros have had plenty of influence on recent elections. And then there are Hollywood and Silicon Valley.

But it is fair to say that MOST people with the capacity to give tens of millions of dollars to political campaigns are Republicans, and this would seem to give the GOP a non-trivial advantage in the post-Citizens United, post-McCutcheon political world. But this assumes the absolute truth of two propositions that we should at least question: first, that more money always translates into more votes. And second, that the Republican fundraising advantage will translate into more money in general (as opposed to primary) elections.

The first assumption violates a basic rule of economics: the Law of Diminishing Returns. It also violates common sense, which tells us that there is some point at which more political advertising ceases to bring any marginal advantage. Two ads might be twice as good as one ad, but 200 ads a day are probably not going to be twice as effective as 100 ads a day. And at some point, the market becomes saturated with your message, and more ads begin to work against you.

good evidence that both the Obama and the Romney campaigns reached this point in Ohio and other highly contested states during the 2012 election. It is unlikely that either candidate could have changed the results at all by doubling, or even tripling expenditures.

An even bigger problem for Republicans, though, is that the influx of money from wealthy donors will not be limited to general elections. Donors will be free to give as much as they want to individual candidates in Republican primaries. This means that tea party and other insurgents will have access to huge piles of cash to use to bludgeon mainstream Republicans, who will have access to even huger piles of cash to use bludgeoning them back, ensuring that anyone who survives a Republican primary will be badly damaged and out of money when the general election begins.

We saw this start to take shape in 2012. When the Citizens United decision unleashed donations to super PACs, Republicans exulted at the advantage they anticipated in the coming election. However, when Sheldon Adelson gave Newt Gingrich $20 million to use to attack Mitt Romney in Florida — and to force him to take extreme positions that would hurt him in the general election — more than a few Republicans regretted their earlier enthusiasm for unlimited donations by billionaires.

Huge infusions of unearned cash rarely work out like people think they are going to. This is the message of Chaucer’s “Pardoner’s Tale,” Dickens’ Great Expectations, and every episode of Behind the Music ever aired on VH-1. The Citizens United and McCutcheon decisions have undoubtedly given birth to a rough beast, and it is just as certainly slouching our way. The problem with rough beasts, though, is that they feel no loyalty to those who gave them birth.